North Korea made a "significant step forward" with a test last week of a new rocket engine that could propel a nuclear warhead to New York or Washington, a report released Monday said.
The influential North Korea-focused website 38 North said images that Pyongyang released on April 9 showing a static jet engine rig observed by leader Kim Jong Un revealed work on a missile that may be able to strike anywhere in the United States.
Calling the test a "disturbing development," the report described the engine as a modified pair of propulsion units from Soviet-era submarine-launched ballistic missiles likely burning a fuel known as UDMH. This material is more calorific than that used in North Korea's medium-range missiles.
"Using this technology, North Korea's road-mobile intercontinental ballistic missile . . . could deliver a nuclear warhead to targets at a distance of 10,000 to 13,000 km," wrote John Schilling, a rocket propulsion specialist.
The lower range puts Los Angeles and Dallas within striking distance, while the upper range includes New York, Washington and Miami.
He said Pyongyang may be able to begin flight tests in about a year and could field nuclear-armed long-range missiles by 2020.
"The only good news from the recent test is that it didn't include a complete first stage," Schilling wrote. The first stage is the section that ignites at launch and contains fuel tanks and other equipment that Pyongyang may or may not have the technology to produce.
"But Kim Jong Un himself was present, and given the likely penalty for embarrassing Kim with a failed test, it is reasonable to suspect the engineers had high confidence from earlier testing."